Perchloric acid a colorless compound is a powerful oxidizer when hot, but aqueous solutions up to approximately 70% by weight at room temperature are generally safe. It is useful for preparing per chlorate salts, especially ammonium per chlorate, an important rocket fuel component. Perchloric acid is dangerously corrosive and readily forms potentially explosive mixture 60% AR ACS Grade 70% AR ACS Grade 70% special Grade for Diamonds